Ube Macapuno Donuts

Ingredients

• 2 tbsp unsalted butter
• ½ cup white sugar
• 2 eggs
• ¼ cup coconut milk
• 2 tsp baking powder
• 1 ½ cups all-purpose flour
• 500 g grated ube
• ½ cup macapuno
• 1 tsp salt
• 3 cups vegetable oil
• ½ cup water
• 3 egg whites
• 1 tbsp macapuno
• 1 tbsp grated ube
• 250 g unsalted butter